PubMed Health⌕ Search

Biomedical subjects

F Boyvat

Publications and source records attributed to F Boyvat.

At least 19 recordsLinked to original sources
PubMed2006

Effect of secondary interventions on patency of vascular access sites for hemodialysis.

PURPOSE: To determine the impact of secondary procedures performed to maintain arteriovenous fistula (AVF) and arteriovenous graft (AVG) patency. METHODS: There hundred and eighty six vascular access procedures were retrospectively evaluated. 156 (40.4%) patients required radiological interventions to treat acute thrombosis, swelling of the extremity with the access site, insufficient hemodialysis, or stenosis at an anastomotic site. RESULTS: The 386 cases comprised 106 AVGs and 280 AVFs. In 138 of the 156 cases, which required a radiological intervention, the treatment was successful and saved the vascular access site. The unassisted post-intervention patency time for these 138 successful cases was 13.1 +/- 12 months (range, 1-65 months). Twenty-nine (63%) of the 46 access sites treated with surgical thrombectomy were saved. CONCLUSIONS: Frequent, regular follow-up of hemodialysis patients with vascular access sites is the best way to diagnose problems early and allow the best chance of long-term function.

Adult↗
PubMed2006

[Hemicentral retinal artery occlusion associated with moyamoya syndrome].

Moyamoya syndrome is a rare cerebrovascular disorder characterized by bilateral progressive supraclinoidal stenosis or occlusion of the internal carotid artery and development of collateral vessels in the lenticulostriate region. The syndrome manifests itself in association with another disease or other clinical symptoms. We present the case of a 12-year-old girl with hemicentral retinal artery occlusion due to moyamoya syndrome associated with clinical and laboratory findings of presumed systemic lupus erythematosus.

Child↗
PubMed2006

Urologic complications in 1523 renal transplantations: The Baskent University experience.

Urologic complications, observed since the beginning of renal transplantation, cause significant morbidity and mortality. In the first few years the procedure was performed, incidence of urologic complications was reported to be 10% to 25%. Recently, the incidence of urologic complications after renal transplantation has decreased to 2.5% to 12.5%; unfortunately, a higher incidence exists in pediatric recipients, reaching approximately 20% with an associated 58% and 74% graft survival rates for cadaveric and living-related transplantation, respectively. We retrospectively analyzed the postoperative urologic complications reported in the medical charts of 1523 consecutive kidney transplantations (1130 men, 74.2%; 393 women, 25.8%; mean age, 31.9 +/- 10.9 years; range, 7 to 64 years; 354 cadaveric, 23.2%; 1169 living, 76.8%) performed by our team since 1975. The first 321 procedures took place at Hacettepe University Hospital in Ankara, Turkey, and the remaining 1202 were performed at Baskent University Hospital in Ankara. Urologic complications occurred in 46 (3%) recipients. Twenty-three (1.5%) of these patients had urine leakage, 15 (1%) had urinary obstruction due to ureteral stricture, 6 (0.4%) had distal ureter necrosis, and 2 (0.1%) developed renal calculi in the late postoperative period. Twenty-four out of 46 required reoperation for urologic complications. The remaining 22 patients were treated conservatively in our interventional radiology department with excellent results. In conclusion, urologic complications will always occur in the posttransplant period. Early diagnosis by experienced personnel and use of interventional radiology can greatly reduce the need for surgical treatment.

Adolescent↗
PubMed2006

Venous complications after orthotopic liver transplantation.

We report venous complications, including portal vein and hepatic vein stenoses, that required interventional radiological treatment in three pediatric and two adult living related liver transplant recipients. Between April 2001 and April 2005, 81 liver transplantations were performed at our hospital. Sixty-two grafts were from living donors. During follow-up, three portal vein stenoses were identified in three pediatric recipients, and two hepatic vein stenoses in two adult patients. In the children, two had received left lateral segment grafts, and one had received a right lobe graft from two mothers and one father, respectively. The etiologies of liver failure were Alagille syndrome, biliary atresia, and fulminant Wilson's disease. Portal vein stenoses were identified at 8, 11, and 12 months after transplantation; all three patients underwent percutaneous transhepatic portal venous angioplasty with a success rate of 100%. The mean follow-up was 102 days; no recurrence has occurred. In contrast, hepatic venous stenoses were diagnosed in two adult recipients. One of them was a 24-year-old woman with autoimmune hepatitis and the other a 43-year-old man with cryptogenic cirrhosis. Hepatic vein stenoses were diagnosed at 3 and 4 months after transplantation. Both hepatic vein stenoses were dilated with balloon angioplasties via the transjugular route. Venous complications identified by Doppler ultrasonography were confirmed by computerized tomographic angiography. Angioplasty represents an effective and safe alternative to reconstructive surgery in the treatment of venous complications after liver transplantation.

Adolescent↗
PubMed2006

A new technique for bile duct reconstruction in liver transplantation.

Biliary complications are one of the most important problems in liver transplantation. Despite various refinements of surgical technique, liver transplantation is associated with significant numbers of biliary problems. In this article, we describe our novel "intraoperative transhepatic biliary catheter insertion" technique for biliary reconstruction in 29 patients, since November 2004 comparing results before and after its implementation. 5-F Kumpe catheter is inserted into the biliary system in two steps. The first is completed at the back table, and the second during the recipient operation. The grafts were from cadavers in 10 cases, with the remaining ones from living donors. Ten patients received whole-liver grafts, 11 received a right lobe, and eight received a left-lateral lobe or left lobe. The mean weight of the living donor grafts was 598 g (range = 270 to 975 g). The mean graft weight-to-body weight ratio in the living donor liver transplantations was 1.6% +/- 1.0% (range, 0.8% to 4.1%). Intraoperative transhepatic biliary catheter insertion was performed with a duct-to-duct anastomosis in 27 cases and with a Roux-en-Y hepaticojejunostomy in two cases. The only biliary complication was one case (3.4%) of bile leakage from the anastomotic site. This rate is significantly lower than that for duct-to-duct biliary reconstructions prior to the new catheter technique (13.0%; P < .05). This new technique of biliary reconstruction with intraoperative biliary catheter insertion has significantly reduced our biliary complication rate. Transhepatic biliary stenting prevents biliary complications and makes it simple to maintain percutaneous access in case such problems arise. However, further studies are needed to compare incidence rates of biliary complications when our novel technique is used versus other surgical techniques.

Bile Ducts↗
PubMed2006

Liver transplantation in children weighing less than 10 kilograms.

Orthotopic liver transplantation (OLT) remains a major medical and surgical challenge in small pediatric patients. From April 2003 through October 2005, 17 infants (each of whom weighed less than 10 kg) underwent the procedure. Four were girls and 13 were boys (mean age, 15.7 +/- 9.3 months [range, 2-36 months]; mean weight at the time of transplantation, 7.4 +/- 2.6 kg [range, 6-10 kg]). All transplants were obtained from living-related donors. Sixteen left lateral segments and 1 left lobe were transplanted. The median graft-to-recipient weight ratio was 3.5% +/- 1.2% (range, 1.5%-6.1%). During the early postoperative period, hepatic arterial thrombosis was identified in 2 infants, and a biliary leak in 1. Hepatic arterial thrombosis was treated by reanastomosis with polytetrafluoroethylene grafting in the first patient and by surgical embolectomy in the second. The biliary leak was treated with percutaneous drainage. In 1 infant, portal vein stenosis, which was identified during the late postoperative period, was treated by percutaneous balloon dilatation. At this time, 14 (82.3%) infants were alive, exhibiting good graft function at a median follow-up of 11 months (range, 2-36 months). Three infants died: 1 on postoperative day 47 from adult respiratory distress syndrome, 1 on postoperative day 12 from sepsis, and 1 on postoperative day 65 from sepsis associated with EBV infection. Episodes of acute rejection, which occurred in 5 patients, were treated with pulse steroid therapy. On follow-up, histologic examination revealed hepatocellular carcinoma in 2 infants and Burkitt's lymphoma in 1 infant. Our data confirm that extensive use of living-related donors in liver transplantation can result in an excellent outcome for small pediatric patients.

Anastomosis, Surgical↗
PubMed2006

Renal autotransplantation for the treatment of complex renovascular hypertension.

OBJECTIVE: In individuals with complicated renal vascular disease, renal autotransplantation has been used as an alternative to percutaneous transluminal angioplasty, which may be unsuccessful or hazardous in these situations. We evaluated the outcomes of renal autotransplantation. PATIENTS AND METHODS: Between February 1989 and December 2005, we performed 5 renal autotransplantation procedures. The surgical strategy included renal explantation, ex vivo renal preservation, ex vivo reconstruction of the renal artery if necessary, and renal heterotopic autotransplantation. RESULTS: The study subjects (3 men and 2 women) exhibited one of the following indications for surgery: fibromuscular dysplasia (2 patients), Takayasu's arteritis (1), or atherosclerosis (2). All patients exhibited uncontrolled hypertension before renal autotransplantation. Renal arteries of patients were anastomosed either to the external or internal iliac arteries or to both when there were multiple renal arteries. The renal vein was anastomosed end-to-side to the external iliac vein, and ureteral reimplantation was not performed. Mean posttransplantation follow-up was 9.8 +/- 5.7 years (range, 1-16 years). Mortality and morbidity were not observed during the follow-up, and hypertension and renal function normalized or improved in all 5 patients. CONCLUSIONS: Renal autotransplantation is a highly effective procedure to treat complex renovascular lesions; ex vivo renal repair is a safe and effective surgical procedure in the clinical setting.

Female↗
PubMed2006

Arterial steal syndrome after orthotopic liver transplantation.

Arterial steal syndrome after orthotopic liver transplantation (OLT) is characterized by arterial hypoperfusion of the graft, which is caused by a shift in blood flow into the splenic or gastroduodenal arteries. In this report, we present mechanisms by which this syndrome caused ischemia in our patients. Steal was suspected by elevated levels of liver enzymes and the results of Doppler ultrasonography and computed tomographic angiography; it was confirmed by celiac angiography. Patients with established hepatic arterial thrombosis before angiography were excluded from this study. Steal was treated by embolization with a coil or by placement of an endoluminal narrowing stent. Ten patients at our institution (seven men and three women; mean age, 24.7 +/- 11 years; range, 6 to 40 years) exhibited biochemical evidence of liver ischemia and graft failure at 1 to 170 days after having undergone orthotopic liver transplantation. Nine of those patients had splenic steal, and one had both splenic and left gastric artery steal syndrome. None of the patients had gastroduodenal artery steal syndrome. The eight patients with splenic steal syndrome and the patient with both splenic and left gastric steal syndrome were treated by transcatheter occlusion with a coil. The remaining patient with splenic steal syndrome was treated with an endoluminal narrowing stent placement. All patients improved clinically within 24 hours after treatment, exhibiting significant changes in their biochemical and radiological parameters. Follow-up ranged from 1 to 22 months (mean, 6.7 +/- 6.6 months). One patient died from sepsis 1 month after having undergone coil embolization. He had no vascular anomalies at the time of death. We conclude that steal is a significant problem after OLT. Embolization and stenting are minimally invasive and successful treatments for steal, usually resulting early clinical improvement.

Family↗
PubMed2006

Stent placement in pediatric patients with hepatic artery stenosis or thrombosis after liver transplantation.

Hepatic artery stenosis (HAS) and thrombosis (HAT) after orthotopic liver transplantation remain significant causes of graft loss. Postoperative HAT follows approximately 5% to 19% of orthotopic liver transplantation. It is seen more frequently in pediatric patients. In the past, repeat transplantation was considered the first choice for therapy. Recently, interventional radiological techniques, such as thrombolysis, percutaneous transluminal angioplasty, or stent placement in the hepatic artery, have been suggested, but little data exist related to stent placement in the thrombosed hepatic artery during the early postoperative period in pediatric patients. Between March 2000 and March 2005, percutaneous endoluminal stent placement was performed in seven pediatric liver transplant patients. HAT or HAS initially diagnosed in all cases by Doppler ultrasound then confirmed angiographically. We intervened in four cases of hepatic artery stenosis and three cases of hepatic artery occlusion. Stents were placed in all patients. Three ruptures were seen during percutaneous transluminal angioplasty of the hepatic artery using a covered coronary stents on the first, fifth day, or 17th postoperative day. In one patient, dissection of the origin of the common hepatic artery developed owing to a guiding sheath, and a second stent was placed to cover the dissected segment. The other two hepatic artery stents remained patent. In one stent became occluded at 3 months after the intervention with no clinical problems. Follow-up ranged from 9 to 40 months. In conclusion, early and late postoperative stent placement in the graft hepatic artery was technically feasible.

Adolescent↗
PubMed2006

Ureteroscopic treatment of proximal ureter stones with the aid of an antegrade occlusion balloon catheter.

PURPOSE: To define the role of an antegrade occlusion balloon catheter in preventing migration of proximal ureteral stones to the dilated proximal ureter during endoscopic treatment. MATERIAL AND METHODS: An occlusion balloon catheter was used in 8 of 21 patients with proximal ureteral stones who underwent ureterorenoscopy. Five of the eight patients had solitary kidneys admitting with anuria and had percutaneous nephrostomy. In the other three patients, percutaneous nephrostomy and occlusion balloon catheters were placed a day before the procedure, since these patients had total obstruction and massive dilatation of the proximal ureter and renal collecting system. The balloons of occlusion catheters were inflated with 1 ml of sterile saline proximal to the stones just before ureterorenoscopy. RESULTS: All stones could be reached by ureterorenoscopy and treated successfully with the aid of an ultrasonic lithotripter, and no stone migration to the upper dilated collecting system was observed. Just after the operation, while the patient was still lying on the operation table, the occlusion catheter was removed. The nephrostomy catheter was removed a day later. All patients were totally stone-free after the procedures. CONCLUSION: Occlusion balloon catheters increase the ureteroscopic treatment success rate in proximal ureter stones. This should be kept in mind especially when dilatation of the proximal collecting system is prominent and in cases with unsuccessful previous intervention with a retrograde stone cone catheter.

Adult↗
PubMed2005

Comparison of two different percutaneous splenic artery interventions in the treatment of hypersplenism: preliminary report.

BACKGROUND: Splenomegaly and hypersplenism occur in patients with chronic liver disease and liver transplant recipients. The traditional treatment for hypersplenism is surgical removal. Percutaneous interventional methods, such as partial splenic embolization, are alternatives to surgery for hypersplenism. This article gives preliminary findings for a new percutaneous technique in which a narrowed stent is placed in the splenic artery. METHODS: The study focused on 10 patients (eight males and two females) who were treated for hypersplenism. Partial splenic embolization was performed in six patients (age range, 1-43 years) who were waiting for liver transplantation, and narrowed stents were placed in four patients (age range, 12-47 years) who had undergone either orthotopic two patients) or heterotopic two patients) liver transplantation. For embolization, the splenic artery was catheterized and polyvinyl alcohol particles were infused to the distal branches, reducing blood flow in the spleen by 40% to 50%. In the other cases, a narrowed stent was deployed to the middle portion of the splenic artery. RESULTS: Hypersplenism was successfully treated in all 10 cases. Compared with partial splenic embolization, placement of narrowed stents was associated with lower frequencies of postintervention fever and pain, shorter hospital stay, and decreased need for antibiotics. In addition to treating hypersplenism, narrowed-stent placement also completely resolved splenic artery steal syndrome in the two patients (orthotopic liver transplant recipients) with this condition. CONCLUSION: Percutaneous placement of a narrowed stent in the splenic artery is a promising new technique for treating hypersplenism and splenic arterial steal syndrome.

Adolescent↗
PubMed2005

Biliary complications and their management in pediatric liver transplantations: one center's experience.

Following living-donor liver transplantation, biliary complications are more prevalent among pediatric patients (<18 years old), with reported rates varying between 15% and 30%. In this study, we retrospectively analyzed biliary complications observed in 21 pediatric liver transplant patients (16 boys [76.2%], 5 girls [23.8%] of ages 1 to 18 years (mean, 8.3 +/- 5.05 years) between September 2001 and June 2004. Biliary reconstruction was accomplished via a duct-to-duct anastomosis in 12 (57.1%) and a Roux-en-Y hepaticojejunostomy in 9 (42.9%) patients. Postoperative biliary complications were encountered in six (28.5%) patients. Four of the biliary leaks were from a duct-to-duct anastomosis and two from an hepaticojejunostomy. One (4.7%) patient who experienced biliary leakage after a duct-to-duct anastomosis developed stenosis after the leak healed; five (23.8%) had the leakage treated successfully. One patient had biliary leakage from the duct-to-duct anastomosis subsequent to a hepatic artery thrombosis. All patients with biliary leakage were treated without surgery. Mean follow-up time was 10.2 +/- 9.6 months (range, 1 to 26 months). Three patients died during follow-up; however, these deaths were not related to the biliary complications. Interventional radiologic approaches are effective to biliary complications, even when the anastomoses are heavily disrupted. In cases of biliary complication, percutaneous combined with internal drainage may prevent biliary sepsis and provide long-term patency.

Adolescent↗
PubMed2005

Vascular complications after liver transplantation in pediatric patients.

Vascular complications are the major cause of morbidity and mortality after liver transplantation, particularly in pediatric patients, owing to their smaller vascular diameters. Between September 2001 and June 2004, among 21 (16 boys and 5 girls) pediatric liver transplantations of mean age 8.3 +/- 5.1 years, hepatic arterial thrombosis (HAT) was diagnosed in 2 (9.5%) patients, and hepatic arterial stenosis (HAS) in 4 (19.4%). Vascular patency was evaluated with Doppler ultrasonography every 12 hours in the first postoperative week and daily in the second postoperative week. When occlusion was suspected, conventional angiography was performed. Thrombectomy was performed in one patient, and thrombectomy and reanastomosis were performed in another patient with HAT. Two patients with HAS were treated with balloon angioplasty. A third patient was treated with balloon angioplasty and endoluminal stent placement at the same time. The last patient with HAS had an intimate dissection, which occurred 24 hours after balloon angioplasty, that was treated with subsequent endoluminal stent placement. Mean follow-up for the patients with vascular complications was 9.5 +/- 5.7 months (range, 4 to 18 months). The overall mortality rate was 14.1% (3/21); however, no deaths were caused by vascular complication. Routine Doppler ultrasonographic evaluation is an effective choice for diagnosing vascular complications seen after liver transplantation. Immediate surgical intervention is required for acute vascular complications, whereas late complications may be treated with balloon angioplasty and/or endoluminal stent placement.

Angioplasty↗
PubMed2001

Covered metallic ureteral stent in the management of malignant ureteral obstruction: preliminary results.

OBJECTIVES: To evaluate the effectiveness of ureteral Dacron-covered metallic stents in the management of malignant ureteral obstruction. METHODS: Covered metallic stents were placed unilaterally using a percutaneous approach in an antegrade fashion into nine ureters of 8 patients with bilateral malignant ureteral obstruction. The contralateral kidneys were drained by percutaneous nephrostomy in 7 patients. The primary diagnoses were rectal cancer in 5 patients and cervical, bladder, and prostate cancers in the remaining cases. RESULTS: Covered metallic stents could be successfully placed in all patients. Only one of nine ureters was stented with a double J-stent. In a mean follow-up of 9 months (range 1 to 14), 7 of 8 patients died because of their primary disease. During the follow-up period, none of the stents were obstructed, displaced, or infected. CONCLUSIONS: Dacron-covered metallic stents appear to be successful in the treatment of patients with malignant ureteral obstruction. The preliminary outcome encourages and justifies the application of this drainage method.

Adult↗